The original Miata debuted in 1989 emphasizing lightweight and precise handling over brute horsepower. Mazda sold over 400,000 units of the first generation model and has continued to advance the design while retaining the original concept over the intervening years. And no version has better captured the spirit of the original Miata than the current, fourth generation MX-5, with an almost 50% increase in power yet close to the same weight as the original. It is in the spirit of this groundbreaking MX-5 that AEM has created a very special intake system, 21-786C, exclusively for the MX-5.
The AEM cold air intake kit is comprised of the aluminum intake tube, heat shield and Dryflow filter
In an effort to remain authentic to the original design, the 2016 Mazda MX-5 is four inches shorter and several hundred pounds lighter than its immediate predecessor. The greatest advancement, though, sits under the hood - the SKYACTIV-G 2.0L engine. With an aluminum block and DOHC cylinder head with variable valve timing and direct fuel injection, the SKYACTIV-G (internal code name PE-VPS) produces 155 horsepower at 6000 rpm and 150 lb-ft of torque at 4000 rpm. And despite the increase in power, the fourth generation MX-5 delivers improved fuel economy over its immediate predecessor.
Clearly Mazda pulled out all the stops to make the fourth-generation MX-5 a world beater, so it would take an extraordinary effort to improve upon excellence. And that was exactly AEM’s goal in developing the 21-786C performance cold air intake system that adds an estimated eight horsepower at the rear wheels.
For this special kit, AEM minimized compromises in some unusual ways. For example, the factory coolant tank was located in the way of the oversized conical air filter AEM engineers had in mind. Instead of rerouting the intake tubing or using a lower capacity filter, either of which would compromise airflow and, as a result, performance, AEM engineers ingeniously developed a relocated aluminum coolant reservoir that’s incorporated into the AEM aluminum heat shield. In addition, the replacement aluminum tank helps provide some additional heat dispersion for the cooling system.
Behind the heat shield is the relocated coolant reservoir which provides extra space for the filter
Fresh air enters the system through the factory inlet and is directed to the oversized AEM Dryflow 21-2157DK air filter. The filter is protected from underhood temperatures by the lightweight aluminum heat shield. Exiting the filter, air travels through intake tubing constructed from mandrel-bent aluminum with a durable gunmetal gray powder coat finish. The all-aluminum construction was selected to remain consistent with the lightweight concept of the MX-5.
This air intake system was developed to accommodate the engine’s factory emissions control devices including the mass air flow sensor and PCV hose.
Development of the filter and intake pipe involved developing and testing the system’s interactions with the factory Mass Air Flow (MAF) sensor to assure it would operate properly and not generate a false “check engine” light. Fittings for both the MAF sensor and PCV hose are attached to the intake tubing.
Development didn’t begin and end on a computer screen. Extensive chassis dynamometer and on-road testing was conducted to confirm both performance and driveability. The end result of AEM's R&D work is a lightweight, functional, easy to install air intake system for the Fourth Generation MX-5 that makes consistent power through the rpm range. In fact, a stock 2016 in AEM’s dyno tests produced 137 horsepower at the rear wheels. With the AEM 21-786C kit installed, powered is increased across the board and with an estimated peak gain of eight horsepower at 4500 rpm. Similar results were observed for torque.
Installation of the AEM 21-786C is straightforward and can be completed within an hour and a half with just a few common hand tools. Factory mounting points are utilized so no drilling is required.
The AEM cold air intake system features a smooth, direct pathway for intake air to the engine
Dryflow synthetic air filters require cleaning every 100,000 miles, depending on driving conditions. When used in dusty or off-road environments, the filters will require more frequent attention. It’s recommended that you visually inspect the filter once every 25,000 miles. Should you notice any partial blockage of the filter, it’s time to clean. To do so, remove the filter, spray it with the AEM Dryflow synthetic air filter cleaner, dry, and reinstall. It’s as simple as that.
The AEM 21-786C is designed and engineered to fit the following vehicles:
2016 MAZDA MX-5 MIATA 2.0L L4 Fuel Injection - All Models